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利用微透析技术,研究盐胁迫下吴屯杨和小胡杨嫩茎质外体中离子的动态变化对气体交换参数的影响。杨树嫩茎质外体离子采用微透析与原子吸收联用进行监测,同时采用Li-6400便携式光合仪进行气体交换相关参数的测定。盐胁迫下,2个杨树品种嫩茎质外体中Na+积累的程度不同,吴屯杨经过一段时间后能够自我调节,减少Na+含量,而小胡杨质外体一直积累Na+,从而造成细胞的渗透胁迫,抑制植物生长;随着盐处理时间的增加,2种杨树K+浓度基本呈现下降的趋势。吴屯杨在100mmol·L-1NaCl胁迫早期光合受抑制的主要原因是非气孔限制,后期是气孔限制;而小胡杨光合受抑制的主要原因是气孔限制。对Na+浓度、K+浓度、Ca2+浓度、Na+/K+、Pn进行相关性分析发现,2个杨树品种Pn均与Na+浓度和Na+/K+比值呈显著的负相关,与K+浓度呈极显著的正相关。以Pn为因变量,以Na+,K+,Ca2+浓度和Na+/K+为自变量,进行多元线性逐步回归分析得统计方程,其中只有Na+/K+对Pn的相关系数有显著意义,方程中只有Na+/K+进入方程,其他3个离子都被剔除。盐胁迫下,吴屯杨耐盐性强于小胡杨,统计方程说明盐胁迫下杨树嫩茎质外体离子变化和光合作用存在共线性关系,且Na+/K+对Pn有显著的线性关系。
Microdialysis technique was used to study the effect of the dynamic changes of ions in the stems of Wu Tun and Populus euphratica under the salt stress on the gas exchange parameters. Poplar tender stem exoplanet ion using microdialysis coupled with atomic absorption monitoring, simultaneously using Li-6400 portable photosynthetic apparatus for gas exchange related parameters. Under salt stress, the accumulation of Na + in two poplar cultivars was different from that in other plants. After a certain period of time, Wu Tun Yang self-regulated and decreased the content of Na +. However, the accumulation of Na + Under osmotic stress, the plant growth was inhibited. With the increase of salt treatment time, the K + concentrations of the two poplar trees tended to decrease. Wu Tun Yang inhibition of photosynthesis early 100 mmol·L-1NaCl stress is the main reason for non-stomatal limitation, the latter is the stomatal limitation; and Populus euphratica inhibition of the main reason is stomatal limitation. Correlation analysis of Na + concentration, K + concentration, Ca2 + concentration, Na + / K +, Pn showed that Pn of both poplar cultivars had a significant negative correlation with Na + concentration and Na + / K + ratio and extremely significant positive correlation with K + concentration Related. Taking Pn as the dependent variable and using Na +, K +, Ca2 + concentration and Na + / K + as independent variables, multiple linear stepwise regression analysis was used to get the statistical equation. Only Na + / K + had a significant correlation coefficient with Pn, K + into the equation, the other three ions are removed. Under salt stress, salt tolerance of Populus euphratica was stronger than that of Populus euphratica, and the statistical equation indicated that there was a collinearity between ion exchange and photosynthesis of exserted poplar under salt stress. Na + / K + had a significant linear relationship with Pn.